Fluid flow control valves

ABSTRACT

A fluid flow control valve intended to be connected between a chamber containing liquid and gas and a suction pump comprises a valve member coupled to float means located in said chamber and a branched passageway communicating on the one hand with atmosphere and on the other with said chamber, the float means serving to move the valve member in the branched passageway whereby in accordance with the liquid level in said chamber the suction pump is connected either with the chamber or with atmosphere.

States Allen et al. 51 Apr. 10, 1973 154 1711111110 FLOW CONTROL VALVES3,018,787 1/1902 101k .137/202 2,710.019 0/1955 Rcasoner ..137/030.15 x[75] hvemorsi Ame; Hamid 3,612,089 10/1971 Beguristain 137/205 Dagwell,both of London, England [73] Assignee: Henry Sykes Limited, London, En-

gland [22] Filed: Apr. 19, 1971 [211 App]. No.: 135,087

[30] Foreign Application Priority Data Apr. 27, 1970 Great Britain..20,l78/7O [52] US. Cl. "137/205, 137/202, l37/630.15 [51] lint. CE...F04h 21/00, F04f 3/00 [58] Field oii Search "137/205, 202, 400,137/423, 630.15

[56] References Cited UNITED STATES PATENTS 2,322,910 6/1943 Adney137/205 X Primary Examiner-Alan Cohan Att0rneyI-la.ll, Pollack & VandeSande [57] ABSCT A fluid flow control valve intended to be connectedbetween a chamber containing liquid and gas and a suction pump comprisesa valve member coupled to float means located in said chamber and abranched passageway communicating on the one hand with atmosphere and onthe other with said chamber, the float means serving to move the valvemember in the branched passageway whereby in accordance with the liquidlevel in said chamber the suction pump is connected either with thechamber or with atmosphere.

3 Claims, 1 Drawing Figure FLUID FLOW CONTROL VALVES BACKGROUND OF THEINVENTION This invention relates to automatic fluid flow control valves,and has particular application to centrifugal pumps of the kind providedwith auxiliary vacuum pumps which assist in priming the pumps andremoving air during subsequent operation. Centrifugal pumps of thiskindare marketed under our trademarks VELOVAC and UNIVAC, and aredescribed in the specifications of our British Pat. Nos. 755,249,1,048,272 and 1,050,893.

With such a centrifugal pump it is important to prevent the waterreaching the vacuum pump, and this involves "the provision of a cut-offvalve usually operated by a float in a chamber. Valve arrangements ofthis type usually have the disadvantage that in their cut-off positionthey completely close the suction passageway to the vacuum pump whichthen runs under heavy load. They also involve complexity and expenseand, unless they are of cumbersome dimensions, can constrict the'suctionpassageway to the vacuum pump which may involve the provision of a morepowerful vacuum pumpthan would otherwise be necessary.

SUMMARY OF THE INVENTION It is an object of the present invention toprovide a control valve arrangement in which the above disadvantages areat least reduced.

According to the present invention there is provided a fluid flowcontrol valve comprising a branched passageway communicating on the onehand with atmosphere and on the other hand with a chamber intended tocontain liquid and gas, a double headed valve member arranged in saidpassageway for movement from a first position in which it closes saidpassageway to atmosphere while opening it to said chamber to a secondposition in which it closes said passageway to said chamber and opens itto atmosphere, and float means disposed in said chamber and coupled tosaid valve member, the arrangement being such that when the liquid levelin said chamber is below a given level the said valve member is in thefirst position, whereas upon rise of said liquid level above the givenlevel the float means serves to cause movement of the valve member tosaid second position.

As a result, when the valve according to the present invention isemployed in a VELOVAC, UNIVAC, or like pump, and the water level risesabove a predetermined level in the suction chamber, the auxiliary vacuumpump is cut off from the chamber and opened to atmosphere. Thus, notonly does the auxiliary vacuum pump run under light load but, also,resetting According to one embodiment of the present invention the saidvalve member is provided with an auxiliary closure means for closingsaid passageway to said chamber, said auxiliary closure means beingmounted for limited movement relatively to said valve member in thedirection of movement of said valve member between the said first andsecond positions, whereby whilst said valve member remains in the firstposition the said auxiliary closure means can be moved into a positionclosing the passageway to said chamber, the said auxiliary closure meansbeing directly connected with a float for moving it into a closingposition upon rise of the liquid level within said chamber, being ofgreater effective area than a part of the valve member for closing saidpassageway to atmosphere and being so constructed that it can undergofurther movement in the closing direction upon initial closure of thepassageway to said chamber, whereby upon movement of the auxiliaryclosure means by saidfloat into an initial closing position, whilst thesaid passageway is sub jected to suction, a reduced pressure isestablished in said passageway which moves the auxiliary closure meansfurther in the closing direction until, upon completion of the availablerelative movement between the auxiliary closure means and the valvemember, the latter becomes moved to open the passageway to atmosphere.Such an arrangement provides a safeguard against exceptional rise ofliquid on failure of the valve member to operate; in such a case theliquid surge would drive the auxiliary closure means into the closingposition, whereupon reduced pressure in the said passageway would serveto draw the auxiliary closure means further in its closing directionuntil the valve member is moved to open the passageway to atmosphere.

BRIEF DESCRIPTION OF THE DRAWING The accompanying drawing is a detailsection view showing a float-operated control valve of a centrifugalwater pump, according to the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to thedrawing, the valve is mounted in top cover 1 of suction chamber 2 of thecentrifugal pump to control fluid flow through passage 3 which leads tothe auxiliary vacuum pump (not shown).

The valve comprises a tubular body formed with a lateral port 5 whichopens into the passage 3, and with a flared lower part 6 which projectsinto the chamber 2.

- Sealing rings 7 are sandwiched between the valve body of the valve tore-open the passageway to the chamber can be effected readily and notagainst the suction of the auxiliary pump.

Suitably, the said valve member is spring urged into said secondposition and a float ofsaid float means is weighted in order to movesaid valve member into the first position under the influence ofgravity, when said liquid level is below the given level. With thisarrangement the valve will fail safe by moving the valve member to saidsecond position under spring action in the event that the float becomesdetached from the valve-operating mechanism.

4 and the recess in the top cover 1 which accommodates the valve body. Acap 8 bolted to the top cover 1 shields the upper end of the valve, thecap being formed with at least one lateral port 9 which opens toatmosphere.

A double headed valve member 10 is vertically movable within the body d,under the action of a float 11. The float, which includes a ballastplate 12, is carried at the end of a pivotal arm 13 mounted on a fulcrumpin 14 which is carried by fixed bracket 15. The valve member 10comprises a vertical connecting rod 16 on which are mounted a tubularupper closure member 117 and a composite lower closure member 1%. Thevalve member 10 is urged upwardly by a compression spring 19 whichreacts against the valve body 4 and engages a retaining plate 20 securedto the top end of the rod 16.

The tubular closure member 17 is slidable along the rod 16 and isarranged to seat, on the one hand, on the top rim of the body 4 and, onthe other hand, on a pilot valve member 21 which is secured, with plate20, to the top end of the rod 16. The tubular body of member 17 isformed with lateral ports 22, and a washer 23 is carried by a shoulder24 on the rod 16 to lift the member 17.

The lower closure member 18 comprises a boss 25 which is sandwichedbetween fixed shoulders on the rod 16 and is formed with an angled upperface 26 which is arranged to seat on seating 27 at the top of the flaredpart 6 of body 4. The member 18 also includes a fail-safe auxiliaryclosure means comprising a float 28 and a rubber disc 29 carried by thisfloat and arranged to seat (as shown) on the flared part 6. The disc 29and its supporting float 28 are slidable along rod 16 between thepositions shown in full and broken lines, respectively.

During normal operation of the centrifugal pump, the water level in thesuction chamber is low and the float 11 is in its down positiq'n asshown in the drawing. The valve rod 16 is likewise in the positionshown, but the float 28 and disc 29 are as shown in broken lines. Inthis position of the valve, the auxiliary vacuum pump extracts air fromchamber 2 through passage 3, the upper valve members 17 and 21 closingthe system to atmosphere, and the dimensions of the lower part of thevalve avoid constriction of the suction passageway from the chamber tothe vacuum pump.

If, during running of the centrifugal pump, the water level in chamber 2rises substantially, the float 11 is also raised and this lifts thevalve rod 16 to open the upper part of the valve and close the lowerpart of the valve. When the rod 16 starts to rise, the pilot valvemember 21 first opens the passage 3 to atmosphere, through ports 22 and9, this movement being assisted by the compression spring 19, and theopening of the pilot valve facilitates the subsequent lifting of thetubular valve member 17 to open the passage 3 fully to atmosphere.Further raising of the valve rod 16 also lifts the boss 25 to close thelower end of the body 4 and so cut off the chamber 2 from the passage 3and the auxiliary vacuum pump. The auxiliary vacuum pump is, however,still open to atmosphere and thus is not heavily loaded.

On return of the water level to its normal low level, the float willfall and re-open the chamber 2 to the passage 3, and this reopening iseffected without the difficulty of overcoming suction (on the disc 29)of the auxiliary vacuum pump as the passage 3 is still open toatmosphere.

Two possible circumstances of failure of the float 11 will now beconsidered.

Firstly, if float failure occurs due to breakage of the arm 13 ordetachment of the bolted float 11, the consequent absence of the ballastplate 12 will result in the spring 19 raising the valve member 10.

Secondly, if float failure occurs due to jamming of the arm 13 or therod 16 or to rupture of a hollow float 11, water would continue to riseinside the chamber 2 and tend to enter the passage 3. However, in thiscase,

the float 28 would be raised to close the flared opening in the valvebody 4 and, due to the flexibility of the rubber disc 29, the suction ofthe vacuum pump would tend to draw the auxiliary closure means furtherinto intimate contact with the flared part 6 and the base of the boss25. Owing to the different effective areas of the disc 29 and pilotvalve 21 the suction of the vacuum pump would also tend to raise thevalve member 10 until the passage 3 is opened to atmosphere.

Modifications may be made without departing from the scope of theinvention. For example, it might be possible to dispense with the mainfloat 11 and rely simply on the operation of the fail-safe seal, inwhich case it might be desirable to provide a larger float 28. In asimplified version, the pilot valve (21) may be omitted and the valvemember 17 fixedly secured to the top end of rod 16.

What is claimed is:

1. A priming device for a centrifugal liquid pump including:

a chamber communicating with the suction side of the pump;

a passageway communicating with a vacuum source;

a first opening from said passageway to said chamber;

a second opening from said passageway to atmosphere;

a double headed valve member of which the valve heads are arranged toclose said first and second openings respectively;

and a float member arranged in said chamber and connected to said valvemember to transmit movement thereto, said float member controlling saidvalve in response to a low liquid level in said chamber to cause saidone valve head of said float member to close said second opening whilemaintaining the first opening open, said float member controlling saidvalve in response to a higher liquid level in said chamber to cause saidother valve head to close the first opening while maintaining the secondopening open;

said valve head for closing the second opening comprising a generallyannular valve head mounted for limited axial sliding movement upon thevalve member,

a valve seat in said second opening at times mating with said annularvalve head, a conduit extending through said annular valve head andterminating in a valve seating coaxial with the valve head, a smallervalve head fixed to said valve member and arranged to cooperate with thevalve seating in said annular valve head, and a helical compressionspring located coaxially around said valve member and said annular valvehead externally of said second opening, said spring being stressedbetween a radially extending abutment of said smaller valve head and thebody of the device defining said second opening so as to bias said valvetoward a position opening said second openmg;

the weight of the float member being sufficient to overcome the force ofsaid spring and hold the valve in the position closing said secondopening when unsupported by liquid present in said chamber.

2. A fluid flow control valve comprising a branched passagewaycommunicating on the one hand with atmosphere and on the other hand witha chamber intended to contain liquid and gas, a double headed valvemember arranged in said passageway for movement from a first position inwhich it closes said passageway to-atmosphere while opening it to saidchamber to a second position in which it closes said passageway to saidchamber and opens it to atmosphere, and float means disposed in saidchamber and coupled to said .valve member, the arrangement being suchthat when the liquid level in said chamber is below a given level thesaid valve member is in the first position whereas upon rise of saidliquid level above the given level the float means serves to causemovement of the valve member to said second position,

said valve member being provided with an auxiliary closure means forclosing said passageway to said chamber, said auxiliary closure meansbeing mounted for limited movement relatively to said valve member inthe direction of movement of said valve member between the said firstand second positions, whereby while said valve member remains in thefirst position said auxiliaryclosure means can be moved into a positionclosing the passageway to said chamber, said auxiliary closure meansbeing directly connected with a second float means for moving it into aclosing position upon rise of the liquid level within said chamber, saidauxiliary closure means being of greater effective area than a part ofthe valve member for closing said passageway to atmosphere and being soconstructed that it can undergo further movement in the closingdirection upon initial closure of the passageway to said chamber,whereby upon movement of the auxiliary closure means by said secondfloat means into an initial closing position whilst the said passagewayis subjected to suction a reduced pressure is established in saidpassageway which moves the auxiliary closure means further in theclosing direction until, upon completion of the available relativemovement between the auxiliary closure means and the valve member, thelatter becomes moved to open the passageway to atmosphere.

3. A valve according to claim 2, wherein the said auxiliary closuremeans comprises a radial plate which is at least partially flexible andresilient, is arranged for limited axial movement upon said valve memberfor cooperation with a flared throat of said passageway, and is directlymounted upon an annular float coaxial with said valve memberand arrangedin said chamber.

1. A priming device for a centrifugal liquid pump including: a chambercommunicating with the suction side of the pump; a passagewaycommunicating with a vacuum source; a first opening from said passagewayto said chamber; a second opening from said passageway to atmosphere; adouble headed valve member of which the valve heads are arranged toclose said first and second openings respectively; and a float memberarranged in said chamber and connected to said Valve member to transmitmovement thereto, said float member controlling said valve in responseto a low liquid level in said chamber to cause said one valve head ofsaid float member to close said second opening while maintaining thefirst opening open, said float member controlling said valve in responseto a higher liquid level in said chamber to cause said other valve headto close the first opening while maintaining the second opening open;said valve head for closing the second opening comprising a generallyannular valve head mounted for limited axial sliding movement upon thevalve member, a valve seat in said second opening at times mating withsaid annular valve head, a conduit extending through said annular valvehead and terminating in a valve seating coaxial with the valve head, asmaller valve head fixed to said valve member and arranged to cooperatewith the valve seating in said annular valve head, and a helicalcompression spring located coaxially around said valve member and saidannular valve head externally of said second opening, said spring beingstressed between a radially extending abutment of said smaller valvehead and the body of the device defining said second opening so as tobias said valve toward a position opening said second opening; theweight of the float member being sufficient to overcome the force ofsaid spring and hold the valve in the position closing said secondopening when unsupported by liquid present in said chamber.
 2. A fluidflow control valve comprising a branched passageway communicating on theone hand with atmosphere and on the other hand with a chamber intendedto contain liquid and gas, a double headed valve member arranged in saidpassageway for movement from a first position in which it closes saidpassageway to atmosphere while opening it to said chamber to a secondposition in which it closes said passageway to said chamber and opens itto atmosphere, and float means disposed in said chamber and coupled tosaid valve member, the arrangement being such that when the liquid levelin said chamber is below a given level the said valve member is in thefirst position whereas upon rise of said liquid level above the givenlevel the float means serves to cause movement of the valve member tosaid second position, said valve member being provided with an auxiliaryclosure means for closing said passageway to said chamber, saidauxiliary closure means being mounted for limited movement relatively tosaid valve member in the direction of movement of said valve memberbetween the said first and second positions, whereby while said valvemember remains in the first position said auxiliary closure means can bemoved into a position closing the passageway to said chamber, saidauxiliary closure means being directly connected with a second floatmeans for moving it into a closing position upon rise of the liquidlevel within said chamber, said auxiliary closure means being of greatereffective area than a part of the valve member for closing saidpassageway to atmosphere and being so constructed that it can undergofurther movement in the closing direction upon initial closure of thepassageway to said chamber, whereby upon movement of the auxiliaryclosure means by said second float means into an initial closingposition whilst the said passageway is subjected to suction a reducedpressure is established in said passageway which moves the auxiliaryclosure means further in the closing direction until, upon completion ofthe available relative movement between the auxiliary closure means andthe valve member, the latter becomes moved to open the passageway toatmosphere.
 3. A valve according to claim 2, wherein the said auxiliaryclosure means comprises a radial plate which is at least partiallyflexible and resilient, is arranged for limited axial movement upon saidvalve member for cooperation with a flared throat of said passageway,and is directly mounted upon an annular float coaxial with said valvemEmber and arranged in said chamber.